To help you decide if the 1994 edition is right for your project, here is a quick comparison:
Consider a 10,000 cfm (4.72 m³/s) system with 50 fittings, 80% elbows, 20% tees. Using the 1994 database at 15 m/s reference: duct fitting database -ashrae 1994- pdf
Here are three professional tricks to get more value from your : To help you decide if the 1994 edition
Includes tables for more than 200 round, rectangular, and flat oval fittings . and flat oval fittings .